The present invention relates generally to a system for evaluating the economic potential of selected animals and, more particularly, to an animal evaluation system that permits an animal being evaluated to move during evaluation rather than being relatively immobilized.
For a number of years, those concerned with animal husbandry, such as farmers, ranchers and the like, have attempted to evaluate the physical characteristics of animals, such as beef cattle, in order to monitor growth and to select those animals with economically favorable traits. Such traits include, among others, the animal's ability to produce meat, milk and other products of a certain type and quality, the animal's ability to convert feed into viable carcass yield, i.e. production efficiency, and the animal's ability to reproduce.
The physical characteristics of a particular animal are generally known to be dependent upon, among other factors, the type and quantity of hormones found within the animal. Hormones are chemical messengers produced by endocrine glands providing secretions directly into the bloodstream which are transported to other parts of the body where they exert a direct effect on peripheral tissues or stimulate other organs or glands. These hormones regulate such important internal processes as growth, muscle development, age of maturity, levels of metabolism, fertility and pregnancy. For example, in beef cattle, the combination of growth hormones and male sex hormones (testosterone) provide for development and enlargement of the muscle systems in the "fore quarters" or "shoulder" area while the combination of growth hormones and female sex hormones (estrogen) provide for the development and enlargement in the muscle system in the "rear quarters" or more commonly referred to as the "stifle" area.
Thus, hormones affect much of an animal's general physical characteristics and so contribute significantly to the animal's economic value. Consequently, research has been conducted to determine, isolate and identify specific hormones appearing in, and the levels of such hormones within, an animal's bloodstreams at particular times and their corresponding bodily effects. This research, however, remains largely incomplete due in part to difficulties in isolating the concentrations and specific types of hormones in an animal's bloodstreams and, given the complex interdependent nature of hormones, difficulties in correlating such presence and quantities with corresponding effects upon present body composition or upon future body composition or both with respect to carcass yield and the animal's ability to reproduce.
Although quantitative correlations between hormone production and physical characteristics of an animal have been difficult to obtain, correlations do appear to exist between certain muscle and bone ratios and certain reproduction and carcass traits of that animal because all depend on the hormone production of the animal though in complex and differing ways. When combined with other physiological measurements such as height and length of the animal's body at given points, correlations between various animal body structures exist.
Physical evaluation of animals has heretofore commonly involved manually measuring specific physical dimensions of such animals and comparing these measurements to averaged values from other animals of a similar kind. In the past, this method involved restraining the animal in an appropriate stanchion, pen or cage so that a technician having a measuring device such as a measuring tape could measure various dimensions of the animal's body. This method, however, has been largely unsuccessful due in large part to unavoidable inconsistencies and inaccuracies in measurements taken by technicians because of the animal's shifting of position between measurements and because of the use of different techniques among technicians.
Recently, image recording systems have been used to obtain physical measurements. In a typical system of this kind, an animal is relatively immobilized by the confines of a chute, not much larger than the animal, in front of a first video camera for recording one side of the animal, and below a second video camera for recording the top side of the animal. Specific skeletal reference points, such as the hook corner of the pelvic bone, the thurl joint which is where the femur bone and the pelvic bone connect, the outermost portion of the stifle and the point of the shoulder are then located by a technician and identified on the animal with reference markers placed on the animal at those locations. The front camera is then activated to record the side profile of the animal and, once this side profile has been recorded, the top camera is activated to record the top profile. A computer then analyzes the video images to provide linear and angular measurements between the reference points for comparison with other animals of similar kind.
Although arguably more accurate than measurements taken by hand, such an image recording measurement system is of insufficient accuracy in providing measurement data on which accurate predictions of animal body compositions can be made. Specifically, in such an image recording system, the measurements remain substantially dependent upon the measuring technician's performance upon the consistent and accurate placement of reference markers upon the animal. This system also does not favorably accommodate for animal posture shifts. In a further shortcoming, the required relative immobilization of the animal during the imaging process prevents rapid sequential measurements of animals in any particular group being measured.